Hmm, well the first thing I’m worried about is with the temp change colder and the fact that you melted it already, is that your getting a lean condition. Did you do a plug chop?
also, is the throttle cable sticking? You can clean them up. They can stick I’d the cable isn’t routed through the space on the bottom of the tank and they can get hung up on the lever end of the carb end above adjustment nuts.
you should plug chop and leak test again to make sure your not lean anywhere. Check your carb cable for sticky spots, and maybe up the mains and try it again at night and see if that makes a difference.
whats everyone else think?